The present invention relates to the processing of cheese products and, more particularly, to a method and apparatus for raising the temperature of individual cheese product slices.
For many years, the so-called xe2x80x9cfast foodxe2x80x9d restaurant trade has offered a variety of food items, typically in sandwich form, that feature a slice of cheese in combination with other foodstuffs. The classic example is the cheeseburger. The cheese slices, usually processed cheese, are conventionally delivered to these restaurants in loaves, comprising from about forty to one hundred sixty slices, and are maintained in refrigeration until shortly before use. As a result, the cheese slices are relatively cold, at about 40xc2x0 F., and because they are stacked in loaves, may not reach room temperature for several hours after being removed from refrigeration.
It has long been recognized that these xe2x80x9ccoldxe2x80x9d cheese slices are undesirable because they tend to reduce the temperature of the cooked beef, poultry or fish pattie when the sandwich is made. As a result, a need has existed for a simple, inexpensive and rapid means for heating the individual slices, while they remain in a stacked xe2x80x9cloafxe2x80x9d form, to raise the cheese slices to about room temperature without in any way altering the physical integrity and appearance of the individual slices and without affecting adversely the ability to peel the individual slices from the stacked loaf.
The present invention is therefore directed to a method and apparatus for warming a stack of cheese slices. In accordance with the invention, the stack of cheese slices is positioned between and in juxtaposition with opposing generally planar electrodes, each of the electrodes having a surface area generally coextensive with that of the cheese stack. Next, a conductive material is interposed between each electrode and the cheese stack to reduce contact resistance. Once properly assembled, an electric current is passed between the electrodes, through both the conductive material and the cheese, thus warming the individual cheese slices through ohmic heating. In accordance with one embodiment of the invention, the conductive material is a moistened paper sheet.
An important aspect of the invention is that the stack of cheese slices is generally uniformly warmed from typical refrigerated temperatures to above about 60xc2x0 F. in a relatively short time period, and this is accomplished while maintaining substantially the physical integrity of the individual cheese slices. Thus, the color, texture, and peelability of the cheese remain substantially unchanged.